Centro Universitário São Camilo, São Paulo, SP, Brazil.
Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Sports Health. 2021 Jul-Aug;13(4):347-358. doi: 10.1177/1941738121998712. Epub 2021 Mar 5.
Caffeine is 1 of the most popular supplements consumed by athletes, and the evidence for improving soccer performance remains limited.
To investigate and update the effects (benefits and harms) of caffeine to improve performance on soccer players.
Electronic search in Medline (via PubMed), CENTRAL, Embase, SPORTDiscus, and LILACS, from inception to March 28, 2020.
Randomized clinical trials (RCTs) assessing the effects of caffeine on the performance of soccer players.
Systematic review with meta-analysis.
Level 1.
Data extraction was conducted independently by 2 authors using a piloted form. We assessed methodological quality (Cochrane risk-of-bias [RoB] table) and the certainty of the evidence (GRADE [Grading of Recommendations Assessment, Development and Evaluation] approach).
Sixteen RCTs were included. Overall methodological quality was classified as unclear to low risk of bias. When assessing aerobic endurance, meta-analyses did not demonstrate the differences between caffeine and placebo (mean difference [MD], 44.9 m; 95% confidence interval [CI], -77.7 to 167.6). Similarly, no difference was observed during time to fatigue test (MD, 169.8 seconds; 95% CI, -71.8 to 411.6). Considering anaerobic power, meta-analyses also did not find differences for vertical jump (MD, 1.01 cm; 95% CI, -0.68 to 2.69) and repeated sprint tests (MD, -0.02 seconds; 95% CI, -0.09 to 0.04), as well as reaction time agility test (MD, 0.02 seconds; 95% CI, -0.01 to 0.04) and rating of perceived exertion (MD, 0.16 points; 95% CI, -0.55 to 0.87). Regarding safety, a few minor adverse events were reported. Based on the GRADE approach, the certainty of this evidence was classified as very low to low.
We found no significant improvement in soccer-related performance with caffeine compared with placebo or no intervention. However, caffeine appears to be safe.
咖啡因是运动员最常使用的补充剂之一，但其提高足球表现的证据仍然有限。
研究和更新咖啡因对足球运动员表现的影响（益处和危害）。
从 2020 年 3 月 28 日起，在 Medline（通过 PubMed）、CENTRAL、Embase、SPORTDiscus 和 LILACS 中进行电子检索。
评估咖啡因对足球运动员表现影响的随机临床试验（RCT）。
系统评价与荟萃分析。
1 级。
两位作者使用经过预试验的表格独立进行数据提取。我们评估了方法学质量（Cochrane 风险偏倚[RoB]表）和证据的确定性（GRADE[评估、制定和评估推荐的分级]方法）。
纳入了 16 项 RCT。整体方法学质量被归类为不确定或低风险偏倚。在评估有氧耐力时，荟萃分析并未显示咖啡因与安慰剂之间的差异（平均差异[MD]，44.9 m；95%置信区间[CI]，-77.7 至 167.6）。同样，在疲劳时间测试中也未观察到差异（MD，169.8 秒；95%CI，-71.8 至 411.6）。考虑到无氧能力，荟萃分析也未发现垂直跳跃（MD，1.01cm；95%CI，-0.68 至 2.69）和重复冲刺测试（MD，-0.02 秒；95%CI，-0.09 至 0.04）、反应时间敏捷测试（MD，0.02 秒；95%CI，-0.01 至 0.04）和感觉用力程度（MD，0.16 分；95%CI，-0.55 至 0.87）方面的差异。关于安全性，报告了一些轻微的不良事件。根据 GRADE 方法，该证据的确定性被归类为极低至低。
与安慰剂或无干预相比，我们未发现咖啡因对足球相关表现有显著改善。然而，咖啡因似乎是安全的。
